What is cervical cancer?
The vast majority of cervical cancers are caused by persistent infections with certain types of human papillomavirus (HPV). HPV is a very common sexually transmitted disease. While nearly all cervical cancers are caused by HPV, not all HPV strains cause cervical cancer. Those that cause cervical cancer are considered high-risk types.
Cervical cancer begins slowly. The earliest, precancerous changes cause the cells lining the inside or outside of the cervix to appear different from normal cervical cells. These atypical, precancerous cells are more likely to progress to cancer if left untreated. If the cells become cancerous, they are initially limited to the surface lining (in situ). Without treatment, the cancer cells can become invasive by growing into the supporting tissues of the cervix and can potentially spread to other body sites.
There are two primary types of cervical cancer. Squamous cell carcinomas, which occur in the flat squamous cells that cover the outside of the cervix, are the most common. They make up about 80-90% of cervical cancers. Most other cases are adenocarcinomas, rising from mucus-producing gland cells of the opening of the cervix (the endocervix). A few cervical cancers are mixtures of both types.
With early detection, cervical cancer is usually treatable by surgically removing the cancer. If early stage cancer has spread beyond the surface of the cervix, treatment may require a hysterectomy, radiation, or chemotherapy. Early treatment cures about 85-90% of women with cervical cancer. Given time, cervical cancer can spread (metastasize) to the rest of the uterus, the bladder, the rectum, and the abdominal wall. Eventually, it can reach the pelvic lymph nodes and metastasize further, invading other organs throughout the body. Cure rates decline as cervical cancer spreads, with extensive cervical cancer usually becoming fatal.
The American Cancer Society estimates that more than 12,900 women develop cervical cancer each year in the United States and about 4,100 die from the disease. Invasive cervical cancer was once a very common disease in the U.S. Since the introduction of the Papanicolaou (Pap) test, a screening tool that allows the detection of cancerous and precancerous changes in the cervix, rates of cervical cancer in the U.S. and other industrialized nations have dropped by as much as 70%. Tests to detect high risk types of HPV have also been developed and are included in screening regimens.
However, in certain populations of the U.S. and in developing nations where access to healthcare and screening programs are limited, cervical cancer is still a very serious concern. According to the World Health Organization, cervical cancer is the second most common type of cancer in women living in developing nations. In these countries, about 445,000 women are diagnosed with cervical cancer and approximately 270,000 die from it.